Plastic Is Fantastic.

Believe it! Designers are creating covetable polymer pieces, applying the forever-futuristic material to party clothes, accessories and even beachwear.

“I love Hollywood,” Andy Warhol once declared. “Everybody’s plastic, but I love plastic. I want to be plastic.”

Apparently Warhol isn’t the only one with synthetic exuberance syndrome. The spring collections are having a decidedly celluloid moment, and designers have decreed that no part of the body shall go unadorned by plastic. From dresses to tunics to short shorts, this season’s garments and accessories are gleaming with acrylic, vinyl and cellophane. Warhol would have been positively giddy.

In Paris, Karl Lagerfeld went plasticus extremis at Chanel, sending several gleaming head-to-toe looks down the runway. One entirely plastic ensemble—a peach-hued pantsuit and green booties—had a distinctly shuffleboard-in-Boca-Raton flair. There was also a shorts and clear vinyl jacket look intended for the beach.

Balenciaga’s Nicolas Ghesquière has conjured up glamorous dresses and skirts that, at first glance, appear to be fringed in feathers. “They feature a unique celluloid material which was created specifically for Balenciaga—each sheet of celluloid has been finely cut to create the delicate fringe,” said Mr. Ghesquière, who found inspiration in a single fringed dress he discovered in the house’s archives from Cristóbal Balenciaga’s winter 1966 collection.

At the Maison Martin Margiela show, models trotted down the runway encased in large dry-cleaner-esque plastic covers. Marc Jacobs opted for polyurethane skirts and plastic cowboy boots and flapper dresses for his spring collection. Mr. Jacobs told reporters after the show that he “didn’t want it to feel real.”

This provocative idea may translate beautifully in the pages of fashion magazines, but is tricky to convert into sales. Plastic ready-to-wear can be “challenging,” said Tomoko Ogura, fashion director at Barneys Co-op. If retailers go to the shows and see “an allover plastic piece and we’re really drawn to the shape, they can develop it in another fabric,” Ms. Ogura said. The result: “a more commercial, salable piece.”

Yet some plastic designs do make the direct leap from catwalk to store rack. For example, shoppers at Neiman Marcus and Bergdorf Goodman can snap up the embroidered plastic mint-green dress and polyethylene coat from Mr. Jacobs’s spring runway show.